Prevent sounds from playing on top of each other.

core/block_svg.js

@@ -982,6 +982,7 @@ Blockly.BlockSvg.prototype.getSvgRoot = function() {
  * @param {boolean} animate If true, show a disposal animation and sound.
  */
 Blockly.BlockSvg.prototype.dispose = function(healStack, animate) {
+  Blockly.Tooltip.hide();
   Blockly.Field.startCache();
   // If this block is being dragged, unlink the mouse events.
   if (Blockly.selected == this) {

core/constants.js

@@ -52,6 +52,12 @@ Blockly.COLLAPSE_CHARS = 30;
  */
 Blockly.LONGPRESS = 750;
 
+/**
+ * Prevent a sound from playing if another sound preceded it within this many
+ * miliseconds.
+ */
+Blockly.SOUND_LIMIT = 100;
+
 /**
  * The richness of block colours, regardless of the hue.
  * Must be in the range of 0 (inclusive) to 1 (exclusive).

core/workspace_svg.js

@@ -131,6 +131,13 @@ Blockly.WorkspaceSvg.prototype.trashcan = null;
  */
 Blockly.WorkspaceSvg.prototype.scrollbar = null;
 
+/**
+ * Time that the last sound was played.
+ * @type {Date}
+ * @private
+ */
+Blockly.WorkspaceSvg.prototype.lastSound_ = null;
+
 /**
  * Create the workspace DOM elements.
  * @param {string=} opt_backgroundClass Either 'blocklyMainBackground' or
@@ -904,6 +911,12 @@ Blockly.WorkspaceSvg.prototype.preloadAudio_ = function() {
 Blockly.WorkspaceSvg.prototype.playAudio = function(name, opt_volume) {
   var sound = this.SOUNDS_[name];
   if (sound) {
+    // Don't play one sound on top of another.
+    var now = new Date();
+    if (now - this.lastSound_ < Blockly.Blockly.SOUND_LIMIT) {
+      return;
+    }
+    this.lastSound_ = now;
     var mySound;
     var ie9 = goog.userAgent.DOCUMENT_MODE &&
               goog.userAgent.DOCUMENT_MODE === 9;